


Enhancing Mana Generation

by WestOrEast



Category: Fate/stay night & Related Fandoms
Genre: F/F, Futanari, Girl Penis, Vaginal Sex
Language: English
Status: Completed
Published: 2020-11-01
Updated: 2020-11-01
Packaged: 2021-03-09 00:48:45
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,969
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27335938
Author URL: https://archiveofourown.org/users/WestOrEast/pseuds/WestOrEast
Summary: Rin's on top of the world now that she's got the beautiful Saber as her Servant. There's plenty of things she plans to do with her, but the first is burying Saber's sword in Rin's stone. All night long.
Relationships: Artoria Pendragon | Saber/Tohsaka Rin
Comments: 1
Kudos: 120





	Enhancing Mana Generation

Rin couldn’t stop herself from rubbing her hands together as she looked Baber over. No, Saber. She should call her Saber. Out loud at least. Even though Baber was _such_ a more fitting name for her. Like, seriously, wow. Rin wasn’t into girls, pfft, no, that was a huge lie, but even among girls, this Saber stood _out_.  
  
“Mistress?”  
  
Oh man, that long blonde hair, those green eyes, that _body_ , oh wow, had Rin lucked out on this Grail War or what?  
  
“Mistress?”  
  
Rin had barely even had time to think about how useful Saber would be in fighting. She was _much_ more interested in how that blue dress flattered Saber’s body without really being crass about it.  
  
“Mistress!”  
  
Rin jerked and blinked, before focusing on Saber. She smiled widely as she stared at that achingly beautiful face.  
  
“Yes, Saber?” Rin asked, licking her lips as she thought about all the fantasies that were already pouring through her head. She wanted to try them _all_ out. She wasn’t sure where she’d get that much peanut butter at this time of night but a girl could still dream, right? “What is it?”  
  
“Do you have any orders for me?” Saber asked in a slightly impatient tone of voice.  
  
“Orders…” Rin said, her mind flashing at the speed of light over to what it would be like to order Saber to strip naked and make sweet, sweet love to her. _Probably_ a bad idea, though. “Well, um, how are you feeling?” Rin looked over Saber’s body once again and could feel herself getting _so_ turned on. “Everything all accounted for?”  
  
“I’m feeling fine, Mistress,” Saber said calmly, crossing her arms underneath her chest with a slight clink.  
  
Oh, _Mistress_. Rin could really get used to being called that by someone as sexy as Saber. She could really, _really_ get used to that.  
  
“Then, um,” Rin _had_ drawn up a list of what she needed to talk to her Servant about once she had summoned her. Where was the list? And what had she put on it? Right now, the only question Rin could come up with was how soft Saber’s lips would feel if she kissed her. “Um, right, we should…”  
  
Rin tried to get her thoughts together as she stared, a smile slowly forming on her face. She barely heard the slight sigh that Saber gave. She did respond when Saber stepped forward and grabbed her shoulder, propelling her forward, out of the basement that Rin had summoned Saber in.  
  
“Perhaps you need to get some rest, Mistress,” Saber said in a fairly flat voice. “I’m sure someone as young as you needs plenty of sleep, especially if you’re often up so late at night.”  
  
Bed. Yes, being in bed sounded good. Being in bed with Saber sounded _great_. Rin was wholly in favor of this new plan and quickly nodded along as she went up the stairs, Saber’s booted feet pounding on the wooden steps behind her.  
  
“Yes, let’s go to bed,” Rin said, wonderfully erotic visions of what would happen to her in her bedroom dancing through her head. “And don’t you need to recharge your mana, too?” Rin’s tongue flicked out to lick her lips.  
  
“I haven’t done anything since being summoned,” Saber pointed out as Rin started for her bedroom, fiddling with her black skirt and red blouse and wondering if she should start to strip out of them right now or get changed into her pajamas and let Saber remove _those_ from her. “I would only need to recharge after a fight or something similar.”  
  
“Yes, but I wouldn’t want you to go into a fight at anything other than your best,” Rin said, climbing the stairs. She turned around to see that Saber wasn’t following her. Well, that wouldn’t do. She reached down and grabbed Saber’s hand, tugging her up along the staircase. “Come on, let’s go!”  
  
They went. Rin couldn’t see Saber’s face, but she could _imagine_ it. And what she was imagining was getting her so _wet_. Oh, wow, Rin was _so_ turned on and she wanted to see Saber _so_ badly. Heck, with what Rin had seen already, she had more than enough fuel to masturbate all night long. But that wasn’t enough. Rin wanted _more_. If it was even remotely possible, then she wanted to actually have Saber take _care_ of her, to do all the things that Rin had dreamed of but had never actually managed to find someone to make happen with.  
  
Rin wished for a moment that she had picked up her room a bit before leading Baber into it. There was a _textbook_ left open on her desk, just making a huge mess, right where anyone could see it. She would just have to hope that Saber wouldn’t, somehow, see the clutter.  
  
“So, um, this is my room,” Rin said, before inspiration struck. “Our room. Yes. Ours. You’ll be sleeping in here with me.”  
  
Did Servants sleep? Rin couldn’t remember. But Saber, at least, wasn’t commenting on it and instead looking at the bed. Rin sat down on it and coughed nervously. An idea was coming to her. And, of course, it was a great idea. She was Rin Toshaka. How could she have any ideas that _weren’t_ great?  
  
“So, um,” Rin said, making sure that her voice did _not_ crack, no matter how much it wanted to, “I don’t own any pajamas. I sleep naked.” She could tell that her cheeks were heating up as stared at Saber but she didn’t look away or give any other sign that she was lying. “So you’re going to have to sleep naked, too.” She paused. “Okay, let’s get to it!”  
  
Her voice rose to a strangled squeak at the last, but it wasn’t _too_ noticeable, was it?  
  
“Of course, Mistress Rin,” Saber said. Rin wasn’t able to read her at _all_ and couldn’t tell if Saber was actually buying this. “Let me undress.”  
  
That instantly made Rin forget all about whether or not Saber was buying what Rin was saying. Her breath caught in her throat and she leaned forward, her eyes going wide as she intently watched, wanting and waiting to see Saber’s naked body, which _had_ to be just as good as it looked underneath her blue dress.  
  
Saber didn’t show any signs of modesty or shame as she stripped out of her clothing. She just _did_ it, quickly removing her clothes and then standing in front of Rin, both hands on her hips.  
  
She was _amazing_. Rin made a sound in the back of her throat like a starving dog seeing a juicy cut of steak as she stared. Everything about Saber, from top to bottom was amazing. Her breasts, her thighs, her face, how it all fit together, oh man, she was so _hot_. Then Rin had time to take in some of the details and blinked as she looked down at Saber’s waist.  
  
“Um,” Rin said, looking down at the large penis that was obviously sticking out from Saber’s crotch. “You have a penis.”  
  
“Yes,” Saber said calmly. “I do.”  
  
Rin thought it over for a microsecond and decided that she did _not_ care. So Saber had a dick. So what? That was just going to give her one more way to make Rin feel good.  
  
Although now that they were actually getting ready to _do_ this, Rin could feel all of her plans just draining away. She wasn’t losing her nerve, not exactly. But she was trying to figure out what was going to happen next. After all, this was a pretty new thing for her. Entirely new, in fact. Thinking about how much she would like to kiss Sakura’s stupid face and almost getting up the nerve to do it once wasn’t nearly enough to get Rin ready for seeing such a hot babe in her bedroom, ready for loving.  
  
“Mistress Rin?” Saber asked. “Are you feeling alright?”  
  
“Gah!” Rin squeaked, shooting up a good half meter from her bed. “Yes, of course I’m feeling alright!” She looked away, a blush coming across her face, half in embarrassment and half in reflexive anger. “Why wouldn’t I be?”  
  
“Then perhaps you would like to get undressed as well, so you can go to sleep?” Saber suggested calmly.  
  
“Yes, right, just let me change-!” Rin remembered, roughly half a second too late, what she had said just a few minutes ago. She laughed shrilly and sat back down on her bed. “I mean, um, you don’t need to call me Mistress, Saber! Rin would do just fine.”  
  
“Of course, Rin,” Saber said with a nod, stepping closer to Rin. “Do you need help undressing, Rin?”  
  
Oh, Saber stripping her naked, carefully removing every piece of clothing and tending to Rin’s naked body… Rin wiped her mouth, making sure that she hadn’t actually started drooling while thinking about that. She took a deep breath and stared up at Saber.  
  
“I, I can manage on my own,” Rin said, forcing her voice to sound somewhat calm and level. “Thank you for the offer.”  
  
As Rin undressed, rather than think about what Saber might think of her own, much more youthful body, Rin focused on the fact that Saber was hard and erect. Rin didn’t know much about how the male half of the equation worked, but she had still gotten a far too good guess from school at what could make the boys there get hard. And if Saber’s reactions and reasons were anything like them, then that would mean that _Rin_ -  
  
That was a nice thought. That was a _really_ nice thought, one that made Rin blush and smile as she got undressed, the confidence from that thought carrying her along without giving her time to worry about what Saber might think of her body. Not that Rin had a _bad_ body or anything. She knew just how pretty she was and how many guys and girls wanted her but couldn’t get her, of course!  
  
And now… it was time to begin. Rin breathed in and out. Okay. She was ready for this. She might have just met Saber a few minutes ago, but someone as hot as Saber was and who was supposed to obey her and _needed_ to have sex to keep on top of her mana pool, well, Rin just _had_ be ready for something as amazing as this was.  
  
“Come over here and get into bed,” Rin said, trying to sound as confident as she normally did.  
  
Saber did, her hips swaying from side to side as she climbed into bed. Rin just couldn’t take her eyes off of how Saber’s breasts swung from side to side as she joined Rin on the bed. And now that they were so close, Rin was finding it harder and harder to think of anything but how _hot_ Saber was and how _close_ she was and how sex was probably going to be everything that she had heard it was going to be.  
  
Taking a deep breath, Rin leaned up and kissed Saber. Kissing another person for the very first time. Oh, it was nice, Rin could tell that even though she was vibrating in nervousness. Saber reached up with one hand and rested it against Rin’s cheek. Rin pushed against it even as they kept on kissing. She could feel Saber’s tongue toying with her lips and then Saber was pushing it inside of her mouth.  
  
Rin realized, once she was halfway down to the bed, that Saber was pushing her down to it. She blinked a she felt her head hit her pillow. And then Saber was hovering over her. And she looked even _better_ from this position, somehow. Rin swallowed heavily as she stared up at her Servant. Saber gave her a very nice smile that made Rin’s heart beat even faster in her chest, somehow.  
  
“You’re very beautiful, Rin,” Saber said, gently lifting one of Rin’s hands and giving it a kiss.  
  
“O-of course I am!” Rin stammered, a blush and a smile appearing on her face. “Everyone’s always lusting after me!”  
  
Saber nodded and ran her hand up along Rin’s arm, then along her shoulder and down to her breasts. And when she touched _those_ , Rin gasped, feeling her mounds being held in a soft, sensitive grip, just firm enough to feel good without any pain. Saber gentle rubbed her breasts, making them feel even better than Rin had ever managed on her own, even the time she had done it in front of a mirror.  
  
Rin could feel her arousal redoubling inside of her, growing into something that was so _hot_ and _needy_ that she could barely believe how turned on she was feeling. Rin moaned, her legs twitching apart to reveal her pussy. She could tell that she was flushed and leaking down there, just waiting for Saber to reach down and make her feel _good_.  
  
“You’re a vision of loveliness like this,” Saber said, her free hand paying attention to Rin’s stomach, going down low but not low enough. “You are such a beautiful girl, Rin.”  
  
Rin nodded, smiling and blushing like crazy. This was feeling _good_. This was feeling really good and she was so glad that she had lucked out with a Servant like this. The thought entered her mind that maybe she didn’t even need to fight in the Grail War. Maybe it could just be her and Saber. Her and Saber leaving the bedroom at some point, even.  
  
Then Saber ran the side of her fingers along Rin’s nipples. Rin made a gurgling sound at that and arched her back, pushing her chest upwards, wanting some _more_ of what Saber was giving her. And she didn’t just want it on her chest. She was _soaked_ down there and wanted something inside of her so badly it was like there was an iron band around her heart that was squeezing tighter and tighter every second it didn’t happen.  
  
“Saber, please,” Rin said with a gasp, her hand twitching downwards to point at her pussy. “I’m ready for you so,” a trace of Rin’s usual attitude resurfaced, “so do your job and make me feel good.”  
  
Saber’s mouth quirked into a quick smile. Then she slid down Rin’s body a bit, grabbing her hard shaft in one hand as she looked down at Rin’s pussy. The close inspection made Rin blush, but she fought down the urge to cross her legs or cover herself up. There was a scarlet blush on her cheeks, maybe not quite as bright as her red sweater, but still _very_ hot. She shivered and tried to catch her breath as she felt Saber looking her over.  
  
Then Saber was getting into position, leaning forward and guiding the tip of her rod towards Rin. All of a sudden, it looked a _lot_ bigger than it had before. Rin swallowed, suddenly feeling a bit nervous at the thought of something so big going inside of her.  
  
“You’d better be careful with me, understand” Rin asked, swallowing as she stared up at Saber’s body. “If this hurts, then I’ll-!”  
  
“I’ll be as slow and gentle as I can be,” Saber promised, reaching down and squeezing one of Rin’s hands. “Just trust me.”  
  
Rin took a deep breath and closed her eyes. Okay. She could do this. She just needed to lay back and let it happen. She looked down at where Saber’s dick was bobbing back and forth and decided it would probably be for the better if she didn’t watch this happening. Instead, she turned her head to one side.  
  
She could feel the hot, hard head of the dick pressing against her entrance. Rin tried to focus on her breathing, remembering her exercises, finding her calm center. She couldn’t actually manage that, but it at least suppressed her nervousness for long enough for Saber to slide in.  
  
And it felt _really_ good! There was still a _stretching_ sensation that made Rin squirm around a bit underneath Saber, but it was just more of a discomfort thing instead of a pain thing. She could handle _that_ , especially when the discomfort was buried underneath so _much_ pleasure. It felt way better than her fingers had as she turned her head to look up at Saber.  
  
Saber was looking down at her with warm, blue eyes, eyes that were full of love and appreciation for Rin. Rin could feel the band around her heart loosen and her breathing seemed to come easier than before. She shivered and moaned, feeling Saber slowly pushing further and further inside of her.  
  
Rin looked down at her pussy, at where she and Saber were _connected_ in the most meaningful way. She shivered, seeing Saber’s thick shaft buried inside of her, out of sight. But she could _feel_ it. She could feel it so much and she loved the feeling of it all, how it was stretching her out and pressing against her inner walls, making it feel better than it ever had before.  
  
And then there was a jolt of pain. Rin gasped, one hand coming to press down on her lower belly. Her hymen. Rin swallowed as she looked down at her flat stomach, as if she was going to be able to see that little fold of flesh.  
  
“Um,” Rin said, before shaking herself and making herself sound more confident. “That’s…”  
  
“Yes, I know,” Saber said softly. “If I break it, it will hurt, Rin.” She cradled Rin’s head in her hand and planted a kiss against her face. “But I’ll be here the entire time for you.”  
  
“Of course you will,” Rin said. “I’m your Master and you’re my Servant.” That little burst of arrogance didn’t really help her current situation, though. She swiftly ran through what she was feeling and what her options were and nodded. “O-okay, Saber. Keep on going. Just, don’t,” her entire body tensed up. “Don’t.”  
  
“Relax, Rin,” Saber said, pressing a kiss to her lips. “Relax as much as you can.”  
  
Rin was _not_ in a state where she could really relax. But she still made an effort, doing her best to try and let the tension flow out of her body as she felt Saber’s dick resting inside of her, stretching her out and pressing against her.  
  
Saber helped her with that, stroking Rin’s body, making her feel nice and tingly inside of herself as her hands and lips brushed against Rin’s body. Rin shivered, feeling the arousal pulsing and growing inside of her, getting stronger and stronger with every breath and a bit of her worry leeching away as well.  
  
Then Saber pressed her hips forward. Rin’s worry came surging back, though not _quite_ fast enough. She opened her mouth to gasp but it was already too late. Saber was through her hymen and the pain was flooding up through Rin’s body, drowning out the pleasure.  
  
Rin screamed, feeling the pain ripping through her as her body tore. Saber was there to comfort her, hugging her tightly and whispering into her ear as her hands stroked Rin’s back. Rin’s own hands were scoring long white lines along Saber’s back as her fingers dug into the well-developed muscles back there.  
  
“Saber!” Rin gasped, tears welling up in the corners of her eyes before she could blink them away. “It _hurts_.”  
  
“I know it does,” Saber said softly. “But just wait, it will be over soon.” She kissed Rin’s cheek, still hugging her tightly as her dick stayed still inside of her body. “Just trust in me and wait.”  
  
Rin shivered and squirmed, but she couldn’t really do anything else _but_ trust Saber. And the pain was lessening, a bit, at least. The arousal wasn’t really coming back, though.  
  
Not until Rin realized that her breasts were pressed up against Saber’s, at least. That helped to get Rin turned on again and she shivered, feeling some heat in her lower body as she felt the stiff nipples pressing against her boobs and the softness that was also there. Her hands slowly relaxed the death grip they had on Saber’s shoulders. Then a thought made Rin lower them down further, to get to Saber’s butt.  
  
Rin hadn’t seen that butt yet and as she felt it, she realized that she had been missing out. It was a _nice_ rear and the way it felt underneath her hands made Rin’s heart beat faster in her chest. Rin did her best to focus on that rear instead of the lingering pain as she squeezed down. Her Servant was perfectly formed in _every_ single way, wasn’t she? That thought helped the lust start to flow inside of Rin once again and she squeezed down lightly, hearing Saber exhale.  
  
“I’m going to start moving again, Rin,” Saber said. “Are you ready?”  
  
Rin thought it over for a second and then nodded. Saber smiled down at her and started to thrust in and out of her again. It still felt so _good_ and Rin moaned as the pleasure abruptly redoubled, drowning out the last remnants of the pain. She could just barely feel it anymore, buried underneath all the pleasure.  
  
Rin leaned up to kiss Saber again. It felt just as good as it had before, their lips pressing together and Saber’s tongue slipping out to run along the insides of her lips. Rin moaned, finally feeling the last dregs of the pain slipping away. There was still the _tightness_ inside of her pussy as she got spread out in ways that she had never been spread out before. But it wasn’t really that bad of a feeling. Rin could live with this. She just had to let Saber keep on working.  
  
And anyway, it was still feeling _really_ good as she felt Saber’s shaft plunging in and out of her, over and over again. Rin moaned, staring into Saber’s eyes as Saber looked down at her, tightly squeezing her hand as they fucked.  
  
“It feels good,” Rin said, feeling her inner walls squeezing down without her even telling them to. “It feels _really_ good.”  
  
“I’m glad it does,” Saber said with a smile that made Rin’s heart beat even faster. “I’m going to make sure it keeps on feeling good for you, too, okay?”  
  
Rin nodded. Saber was gradually picking up speed. Not really going _fast_ , but at least faster. And it was starting to really feel good. Rin moaned, her hands squeezing down on Saber’s butt, her shoulders, her hands, everywhere that they could reach. She could feel something _wonderful_ forming inside of her. It took a minute for Rin to realize that it was her orgasm. It hadn’t even happened yet and she could already tell that it was going to be a lot better than any that she had ever got to feel before in her life.  
  
“I’m going to cum,” Rin mewled, staring into Saber’s eyes and seeing the same lust that she was feeling in them. “I’m going to _cum_ , Saber!”  
  
“Let yourself cum, Rin,” Saber said, pushing herself up on one arm to look down at Rin. Rin’s eyes went down to Saber’s breasts and lingered there for a while before she could get herself to look back up. “Just enjoy it.”  
  
Rin didn’t need permission to cum, but Saber’s words still helped push her over the edge. She gasped as she felt the orgasm taking form inside of her. It was hot and it was wonderful and she couldn’t believe how happy she was feeling to get to have this happen to her. She moaned, feeling her inner walls squeezing down _tightly_ around Saber’s shaft, squeezing with more force than Rin would have thought her body was capable of.  
  
Rin had been right. This was the best orgasm that she had ever gotten. It _screamed_ through her, making her gasp and whine as stars turned themselves on and off in front of her eyes. The pleasure that was coursing through her body was more intense than masturbation had ever been and Rin loved it _so_ much.  
  
And Saber was fucking her straight through the orgasm. She was still going pretty slow and it was still feeling _good_ as her dick slid in and out of Rin again and again, making the orgasm last for even longer and making Rin _melt_ as she got to feel the sensation of the dick moving in and out of her.  
  
Rin stared up at Saber with wide eyes as she felt the pleasure surging through her. Saber was kissing her and saying words to her that Rin just couldn’t focus enough to make out. And as she went, she kept on making Rin feel _good_. Not just sexually, but the closeness of Saber’s body and how she was holding Rin and _everything_ made Rin feel so happy that she couldn’t even think of the words she would need to use to describe how good she was feeling.  
  
“I love you,” Rin gasped out, staring up into the eyes of this beautiful woman who was doing so _much_ for her. “I love you so much, Saber.”  
  
“I love you too, Rin,” Saber said quickly and easily, kissing Rin again as she kept on fucking her. “Just relax and let me take care of this.”  
  
Rin nodded and leaned back, her head resting on the pillow as she felt Saber’s thrusting start to vary. Was she- Rin realized that Saber might be about to cum as well. Rin was still riding high on the best orgasm of her life and now she was going to get to feel the hottest woman in the world cumming inside of her. This had to be the best night of Rin’s _life_.  
  
Saber sped up, moving in and out of Rin faster and faster. It was a _bit_ uncomfortable, but not enough to really worry Rin. And then Saber grunted, pushing herself as far inside of Rin as she could go. That was also a bit uncomfortable, but again not enough to make Rin worry. Not when she could feel Saber’s cock twitching inside of her.  
  
That was _quite_ the experience and made Rin gasp and giggle. Which quickly trailed off into a moan as she felt the semen start to flow inside of her. It was _hot_ , it was far hotter than Rin had thought it could possibly be. And it felt good, covering Rin’s walls and making her squirm underneath Saber as the blonde woman held her in place, peppering her face with kisses.  
  
Rin felt like she was walking on sunshine. This was _amazing_. It was the best thing to have ever happened to her, ever since she had seen Saber in the summoning circle. She was willing to do _anything_ to have this happen again. And to do anything for Saber. She wrapped her arms around Saber as she felt the stiff dick still spreading out her insides. And there was the _cum_ that was there as well. Rin just couldn’t forget about Saber’s semen filling her up. It felt _way_ better than she thought it possibly could have.  
  
Saber gentle lowered herself down until she and Rin were wrapped up in each other’s arms on the bed. Rin took another chance to look Saber over and _still_ couldn’t believe that Saber looked this hot. She was _beautiful_ and she was _Rin’s_.  
  
Rin was feeling horny enough to want to go for another round. Not _right_ now, but just as soon as she caught her breath and her heart stopped pounding, she would be more than ready to spend some more time with this amazing woman. And since Saber’s saber was still half-hard and covered in Rin’s arousal and her semen, Rin was certain that Saber was just as willing to go again and again, until the sun was rising.  
  
“That felt wonderful, Rin,” Saber said, running a hand along Rin’s cheek. “You’re such an amazing young woman.”  
  
“Well, of course I am,” Rin said, though without the usual heat that would come at the implication she could be anything but the best. “I’m a once in a lifetime genius, after all, summoning a Servant as strong as you!”  
  
Saber didn’t say anything and just hugged Rin. And Rin decided that this was more than enough. She returned the hug, pressing up close against Saber and feeling her heart beating in her chest. She wondered if Saber could feel it as well.  
  
Burying her head in Saber’s shoulder, Rin slowly let out a breath that she hadn’t even known she had taken. This was nice. This was _really_ nice. She wiggled around a bit and got more comfortable against Saber’s body and just _relaxed_ , feeling the stress and tension melting out of her. With a Servant like Saber on her side, was there any way that Rin couldn’t get everything she wanted?  
  
Including getting some things that Rin hadn’t even realized she would want so strongly. What she was feeling inside of her, oh, it was just so _wonderful_. She giggled and pressed herself even more firmly up against Saber. She was getting her breath back, which meant that pretty soon, it was probably going to be time for some more _fun_.  
  
Rin decided that she was going to make sure that Saber stayed on top of her mana recharging issues _perfectly_. That she was going to make sure that her Servant never once needed to worry about running out of mana. And that she was going to enjoy doing that the entire time, well, that was just…  
  
The real reason she was doing, Rin admitted. But so what?  
  
This Grail War was going to be dangerous enough as it was. She deserved a few little treats and benefits for it.


End file.
